#include<iostream>
#include<string>

using namespace std;

char toAlph(string str) {
    // cout << str << endl;
    return stoi(str) + 'a' - 1;
}
string freqAlphabets(string str) {
    int idx = str.size() - 1;
    string tmp, res;
    string n1, n2;
    while (idx >= 0) {
        if (str[idx] == '#') {
            idx--; // skip #
            n2 = str[idx];
            idx--;
            n1 = str[idx];
            idx--;
            tmp = n1 + n2;
            res = toAlph(tmp) + res;
        } else {
            tmp = str[idx];
            idx--;
            res = toAlph(tmp) + res;
        }
    }
    return res;
}
int main() {
    string str = "1326#26#";
    int idx = str.size() - 1;
    string tmp, res;
    string n1, n2;
    while (idx >= 0) {
        if (str[idx] == '#') {
            idx--; // skip #
            n2 = str[idx];
            idx--;
            n1 = str[idx];
            idx--;
            tmp = n1 + n2;
            res = toAlph(tmp) + res;
        } else {
            tmp = str[idx];
            idx--;
            res = toAlph(tmp) + res;
        }
    }
    cout << res << endl;
}